Convertible printing press



Jan. 20, 1942. w, w. vmso 2,270,273

CONVERTIBLE PRINTING PRESS Filed Sept. 6, 1939 Patented Jan. 20, 1942UNITED STATE s I PATENT OFFICE CONVER TIB LE PRINTING PRESS I WilliamWard Davidson, Evanston, 111.

Application September 6, 1939, Serial No. 293,554

6 Claims.

The present invention relates to printing presses generally and moreparticularly to presses which are convertible to perform differentprinting processes.

Three common classes of printing processes are: lithographic, intaglio,and type printing.-

With more and greater uses being'made of commercial printing, it hasbecome increasingly important that users or printers have one or twoconvertible presses to take care of their requirements rather than agreater number of presses which are limited in their operation to theperchangeable upon one cylinder and the litho-.

graphic plate of another cylinder is converted into an ink form rollersurface for the type segment, whether the press be of two cylinder orthree cylinder construction.

Another purpose of the invention is to provide a press which isconvertible without need for changing the inking mechanism of the press.1

Moreover, I provide a convertible press with these characteristics thatprints the paperupon the same side whether it is the bottom or the top.

Other objects will become apparent from the drawing, the descriptionrelating thereto and the claims.

Referring now to the drawing:

Fig. 1 illustrates a two cylinder rotary press set up for indirectlithographic printing;

Fig. 2 illustrates the press shown in Fig. 1 conv verted for direct typeprinting;

Fig. 3 illustrates a three cylinder press embodying the invention as setup for indirect lithographic printing; and r Fig. 4 is a press shown inFig. 3 as converted for direct letter press work.

Broadly speaking, without changing the inking characteristics of thehiking unit or its osition I convert the blanket cylinder of alithographic couple into a direct or type printing cylinder andinterchange the plate of the couple with a composition covering whichcooperates with the inking unit as an added form roller for the typeprinting cylinder.

In Figs. 1 and 2 this convertibility is shown in relation to a twocylinder press comprising a printing couple with a blanket cylinder llocated above a larger cylinder H having a platen segment 12 and a platesegment l3. Blank sheets of paper are fed from the conveyor board I bythe feed rollers l5 which are synchronized to feed a sheet into the biteof the cylinders between the platen i2 and the, blanket III. A leadingoverlap of the sheet is provided at the gap l6 so that the stripper I!may be tilted into the gap to catch the leading edge of the sheet anddirect it onto the delivery table H.

The ink applying rollers are indicated at and comprise the fountainroller 2|, the ductor roller 22, the distributor roller 23 and the inkform when 24. The water damping mechanism comprises the fountain roller25, the water ductor roller 26, the water distributing roller 21 and thewater form roller 28. The form rollers 24 and 28 are lifted to clear theplaten l2 each revolution of the cylinder II by a cam 30 thereon whichdoes not engage cylinder ID or affect the tion covering 32 is fastenedin its place.

covering is preferably surfaced with a material pressure of the printingcouple.

As shown in Fig. 2, whenever it is desirable to convert the two-cylinderembodiment into a direct or type press, the blanket is removed from theblanket cylinder l0 and a cast type plate 3| is slipped endwise onto thecylinder Hi, the frame work of the press (not shown) being cut away topermit this.

The plate I3 is then removed and a composi- This similar to that uponthe form roller 23 and when in operation the form roller 23 becomes insubstance a second distributor roller and the covering 32 becomes theform roller.

Thus, when the conversion is made for direct and letter type printing,the inking system remains physically unchanged although greaterdistribution is had, and it remains only to remove the water form rollerfrom contact with the cylinder II to place the press in full operationfor direct printing.

In both forms of the conversion, whether the form in Fig. 2 isconsidered the initial construction adapted to be converted forlithographic printing, or whether the form in Fig. l is consideredtheinitial construction, conversion may be had readily and quite easilyeven by persons unskilled in printing, and in both cases the blanksheets are printed on the same side, in this instance-upon the upperside.

Referring nowto Figs. 3 and 4, a three cylinder press is illustrated asconverted from performing one form of printing to performing another.The numerals and description relating to water and ink distributionremain the same, ex-

are located at the top of the press where they are open forready'inspectlon.

The three cylinders comprise in the lithographic printing couple theplate cylinder 40 at the top, the platen 4 at the bottom, and a blanketcylinder 42 between them.

In this embodiment, the contour .of a side frame is indicated in brokenlines 43 in Fig. 4. The side frame at least on one side of the press iscut away to permit the endwise movement of the cast type segment 44 tobe moved into and out of place upon the intermediate cylinder.

Whenever it is desirable to change one form of printing to another, theplate 45 is interchanged with a composition ink distributing covering t6and the blanket 41 is interchanged with the cast type segment 44.

In both'the three and two cylinder constructions, I prefer to have theconversion performed in relation to the pitch line of the meshing gearteeth. In doing this, the bed surfaces supporting the plates in theseveral views are relieved enough to accommodate the thickness of thecomposition coverings 32 and 46 without changing the printing radius ofthe cylinders. With this construction, I provide a foundation coveringfor the bed when the plates are mounted. 'Ifhis foundation may besecured to the plate before mounting or, as preferred, is fastened overthe bed surface before the plate is mounted.

In this Way I adjust for and maintain the proper printing couple line ofpressure contact in relation to the pitch line of the gear teeth drivingthe cylinders for both forms of printing,

on either the two cylinder or the three cylinder press.

In some instances it is desirable to have multigraph type upon theblanket cylinder. I

taining the relationship between the line of the In mainwith the pressesthat are intended for multigraph conversion.

-Having described several embodiments of the invention and suggested themanner in which they are believed to function and operate, it will beapparent to those skilled in the art that var-' ious uses,modifications, and changes may be made therein without departing fromthe spirit and substance of the invention, .the scope of which iscommensurate with the appended claims.

What is claimed is: 1

1. A convertible printing press comprising a small cylinder disposedabove a large cylinder, interchangeable blanket and direct printingmeans for the small cylinder, a platen surface upon the large cylindercooperating with the small cylinder to provide a printing couple,interchangeable plate and ink form surfaces for the large cylindercooperating with the small cylinder to provide an ink transfer medium,and

means for inking the interchangeable surfaces upon the large cylinder.

6 2. A printing press comprising a blanket cylinder supported abovetheline of feed of paper to the printing couple, a larger cylinderdisposed below said line of feed and providing a platen surface and aplate surface cooperative'with the 10 blanket cylinder for lithographicprinting, an

inking mechanism contacting the plate surface each revolution of thelarger cylinder, ink form surface means interchangeable with theplate,and direct printing means interchangeable with the blanket.

3. A convertible printing press for lithographic offset printingordirect printing, comprising a small cylinder and a cooperating largecylinder, a blanket surface on the small cylinder interchangeable withdirect-printing means, a platen surface on the large cylinder, and alithographic plate surface on the large cylinderinterchangeable with anink form surface.

4. A convertible printing-press for lithographic offset printing ordirect-printing, comprising a small cylinder and a cooperating largecylinder, a blanket surface on the small cylinder interchangeable withdirect-printing means, a platen surface on the large cylinder, alithographic plate 30 surface on the large cylinder interchangeable withan ink form surface, and an inking mechanism for supplying ink to aportion of the large cylinder whether that cylinder'supp rts alithographic surface'or an ink form surface.

offset printing or direct printing, comprising a printing coupleconsisting of a small upper cylinder and a cooperating lower cylinderhaving a diameter twice that of the small cylinder, a

40 blanket surface on the small cylinder interchangeable withdirect-printing means,- a platen surface on the lower cylinder, alithographic plate surface on the lower cylinder interchangeable with anink form surface, and an inking mechanism associated with the lowercylinder for supplying ink to a portion of said lower cylinder whethersupporting a lithographic surface or an ink form surface.

6. A convertible printing press for lithographic n offset printing ordirectprinting, comprising a small cylinder and a cooperating largecylinder,.

a blanket surface on the' srnallfcylinder interchangeable withdirect-printing .nicans a platen surface on the large cylindrffalithographic plate surface on the large cylinder interchangeable with aninig'form surface, a single inking -mechanism for'supplying ink foreither of said "types of printing, said inking mechanism being arrangedto apply ink directly to the lithographic m plate surface when the pressis doing lithographic offset printing, and to the ink form surface whichin turn transfers the ink to the direct-printing means when the press isdoing direct printing.

' WILLIAM WARD DAVIDSON.

5. A convertible printing press for lithographic

